Investigation of the reduction roasting of saprolite ores in the Caron process: reaction mechanisms and reduction kinetics

Abstract

Laboratory studies have been undertaken to investigate the mechanisms and kinetics of reactions occurring during the reduction roasting of saprolite ores. Reduction was undertaken using a H₂/N₂ gas mixture at temperatures between 400 and 800°C. The focus of the study was to determine the effect of dehydration, reduction, sintering and olivine recrystallisation reactions on nickel recovery. The effects of thermal history, temperature and time on the rates and extents of these processes have been investigated. The results provide valuable insights into the relative contributions of the elementary processes taking place during the reduction roast process, and help to explain some of the behaviour observed in industrial practice.